1. Field of the Invention
The present invention generally relates to the field of manufacture and assembly of circuit boards. More specifically it relates to a method of transferring component tape information to a component mounting machine, a tape guide for guiding a component tape in a component mounting machine, and a tape magazine for receiving the tape guide.
2. Description of Background Art
Generally, within the field of manufacture and assembly of circuit boards, electronic components are fed to a component mounting machine for mechanically and/or electrically mounting the components onto a circuit board. These surface mounted components are often delivered spaced apart along the length of a component tape, which consists of a lower carrier tape provided with compartments, one for each component, and an upper cover, or cover tape or protective tape. After positioning the electronic components in the corresponding compartments, the cover tape is attached to the carrier tape, and the component tape is wound on a component reel. The attachment of the cover tape to the carrier tape can, for instance, be performed by providing either the cover tape or the carrier tape with adhesive areas, or by fusing the cover tape to the carrier tape. Then, the component reel is transferred to a component mounting machine, which is provided with feeding mechanisms for feeding a component to a certain predetermined picking position where it can be picked, or collected, by a pick-up head. Alternatively, the component reel can be transferred to a component tape magazine, which in turn is inserted into the component mounting machine. Then, it is generally the magazine that is equipped with the feeding mechanisms for performing the described feeding of the component tape. WO 86/00778 shows a cassette magazine for a component mounting machine using the above described method.
Generally, a circuit board is provided with a wide variety of different components, and a component mounting machine can be used for the manufacturing of a variety of different circuit boards. Therefore, a substantial number of different types of components are provided to a component mounting machine, wherein each type of component is contained on a separate component tape. The component mounting machine, or the process controlling the machine, must therefore know exactly which type of component can be found at which picking position in the machine. Traditionally, following the loading of a component tape into a component mounting machine or a tape magazine, this is performed by manually entering the position and the type of component of each component tape into memory means used by the machine. This time consuming process must be performed each time a new component tape is loaded into the machine.
Furthermore, when entering the position and component type manually, there is always a considerable risk of entering the wrong type of component or the wrong position. This would inevitably lead to circuit boards being erroneously mounted, or lead to a halt in the manufacturing process until the error has been corrected. In recent years, the use of bar codes has simplified the above-described process. When the component tape has been loaded into its position in a component mounting machine, the position and the type of components are entered by reading both a bar code provided at each tape position in the machine, and a bar code provided on the component tape reel. Still, this process has to be repeated each time a new component tape is entered into the machine, and the risk of reading the bar code for an adjacent, incorrect position in the machine is still there, even though the use of bar codes reduces the risk involved with the above-described process.
When using a tape magazine, a component tape reel is loaded at each of a number of different positions in the magazine. Information regarding the position of the tape reel and the type of components contained on the reel is entered into the machine for each position, along with the magazine identity. Thereby, when switching between two magazines, entering the identity of the new magazine can be sufficient, provided that the positions and type of components of the component tapes have not changed since the magazine were last used. Any change would again require the entering of at least the position and the component type.
It is also preferred if the component mounting machine have knowledge of have many components there are left on the tape in order to optimise the mounting process, and to alert in time that a component tape is about to run out of its components. This information can also be entered manually upon loading a new tape into the machine. Then, the machine could count the number of components that have been picked from the tape and, thereby, derive the number of remaining components on the tape. However, if the component tape is removed from the machine, e.g. when replaced by a type of component needed for a particular circuit board, this information is lost.
According to the method conventionally used within the art, the loading of a component tape in a component mounting machine involves the following steps. Placing the component tape reel into the tape holder of a component mounting machine, or into a tape magazine of a component mounting machine; introducing the free end of the component tape into a feeding mechanism, provided in the machine or in the magazine, such that feeding pins engage corresponding holes provided in the component tape; separating, by hand, the end of the cover tape from the end of the carrier tape for a distance sufficient for the cover tape to be engaged with a cover tape handling means; and lowering a locking mechanism over the carrier tape for holding the carrier tape against the feeding mechanism.
As realised from the above, the loading of a component tape in a component mounting machine and the related entering of component information is a time-consuming process that has to be performed every time a new component has to be added to the circuit board manufacturing process, and every time an empty component tape has to be replaced. The process is also connected with a certain element of risk regarding errors in relation to the more or less manual entering of information. This negatively affects the overall time efficiency of the manufacturing process and, hence, the overall costs.
It is therefore an object of the present invention to provide a solution to the problem of time-consuming loading of a component tape and the related entering of component information into a component mounting machine.
A further object of the present invention is to significantly reduce the risk of errors occurring during the entering of component information into the component mounting machine.
A still further object of the present invention is to achieve a higher degree of flexibility related to the loading of component tapes into a component mounting machine.
This and other objects are achieved according to the present invention by providing a method, a tape guide, and a tape magazine having the features defined in the independent claims. Preferred embodiments are defined in the dependent claims.
The present invention is based on the insight of providing a tape guide, for guiding a component tape in a component mounting machine, with the ability to be releasably mounted, such that the loading and/or unloading of a component tape into and from the tape guide can be performed away from the component mounting machine, and with identification means for holding the identity of the tape guide. Preferably, the ability to be releasably mounted is achieved according to the present invention by providing a tape guide with locking means for ready and quick attachment and detachment to interacting locking means in a component mounting machine, or in a tape magazine arranged for insertion into a component mounting machine, and guiding means for guiding a component tape.
By providing a tape guide with the ability to be loaded with a component tape away from a component mounting machine and to be subsequently loaded into the component mounting machine, a facilitated loading of the component tape into the machine, a reduced downtime of the machine, and, thereby, an improved time efficiency of the entire manufacturing process is achieved. This is due to the fact that the time-consuming process of loading the component tape into a component mounting machine, as described above with reference to known art, is reduced to simply placing a component tape reel into the tape holder of a component mounting machine, and mounting a tape guide into the machine. The rest of the loading process is performed beforehand and away from the component mounting machine. Thus, the downtime of the component mounting machine due to the loading of a component tape is limited to the actual time for placing a tape reel into the machine, and for loading a tape guide into the machine, which increases the time efficiency of the machine considerably.
Furthermore, by providing the tape guide with identification means, the tape guide identity can be associated with information regarding the specific component tape that is, or is to be, loaded into the tape guide. Hence, the identity of the tape guide will be the key to the information that is essential to the component mounting machine, namely the type of components carried by the component tape.
According to the invention, the identity of the tape guide is associated with information regarding the component tape that is loaded into the tape guide. As mentioned above, this is performed away from the machine at any time before the attachment of the tape guide into the component mounting machine, or into a tape guide magazine for subsequent insertion into the machine. Thereby, the entering of information does not interfere with the loading of the component tape and the tape guide into the machine.
Preferably, the component tape information is provided in the form of bar codes holding the necessary information. Said bar codes are advantageously applied on the tape reel containing the component tape. Accordingly, the tape guide is preferably provided with a bar code holding the identity of the tape guide. As evident to the man skilled in the art, other forms of information holding means can of course be used without departing from the inventive concept of the present invention. The association of the tape guide identity with the component tape information is performed by simply reading the bar codes with a bar code reader and storing the identity together with the component tape information.
According to an alternative embodiment, the bar codes of the component tape, which can be one or a number of bar codes, are read by a bar code reader and associated with an identity of the tape reel. A bar code can then be produced, relating only to the identity of the component tape or tape reel. Thus, when loading the component tape into a tape guide, only the identity of the component tape or tape reel has to be associated with the tape guide identity, due to the fact that the identity is associated with the component tape information.
According to the invention, the component tape information comprises information regarding which type of components that is provided on the tape. Preferably, the information also contains the number of components provided on the tape. However, there is more information regarding the component tape that can be useful for the component mounting process. These data could for instance include component tape identity, batch number, intended customer, manufacturer of the component tape or of the component, the width of the tape, the pitch of the tape, characteristics of the components on the tape, etc. The characteristics of the components could include resistance, manufacturing tolerances, etc.
According to the invention, the essential information regarding the tape guide is the tape guide identity. However, this could preferably be associated with characteristics of the tape guide, e.g. width of tapes that can be loaded into the tape guide, type of exposure means, batch number, etc.
As described earlier, the tape guide is provided with the ability to be quickly and readily attached and detached into and from the component mounting machine, or a tape guide magazine. According to the preferred embodiment of the invention, means holding information of the identity of the tape guide is automatically connected to means provided in the machine, or in the magazine, for receiving that information, when the tape guide has been mounted into the machine, or the magazine. This is preferably performed by providing the tape guide with identification means in the form of a circuit holding the identity of the tape guide. Said circuit can for instance be provided with contact surfaces, which automatically are connected to corresponding contact pins coupled to identity reading means in the component mounting machine or in the magazine, whereby the identity of the tape guide is read by the machine or the magazine. Said connection could also be an optical connection, or any other suitable connection as realised by the man skilled in the art.
This means that the machine not only receives information regarding the identity of the tape guide that has been mounted into the machine, but also has access to all information associated to the identity of the tape guide. Furthermore, the machine can sense into which position in the machine the tape guide has been mounted. Thereby, there is no need for entering the position of the tape guide into the machine, which means that the risk of entering the wrong position is eliminated. Furthermore, there will never be any risk of mounting a tape guide into the wrong position of the machine, and, when replacing several tape guides, the position into which the new tape guides are mounted are unimportant. This increases the flexibility of the mounting of tape guides into the machine and considerably reduces the risk of making mistakes upon mounting of tape guides. Thus, the replacement and entering of component tapes into a machine can be more speedily performed and the downtime of the machine can be reduced.
When using a tape guide magazine, the position and identity of each tape guide mounted in the magazine are read by the tape guide magazine. This information, i.e. the tape guide identity for each position in the magazine, is then transferred to the component mounting machine when the magazine has been inserted into the machine. Alternatively, the information is relayed directly to the component mounting machine, via a connection provided in the magazine, without actually being read by the magazine. Further, information regarding the identity of the tape guide magazine can be added to the transferred information. This can be performed by any suitable means for transferring information, as realised by the man skilled in the art, and will therefore not be further described.
The required features of the tape guide for enabling the loading of a component tape away from the machine and the subsequent loading of the tape guide, with the component tape, into the machine comprise locking means for ready and quick attachment and detachment of the tape guide into and from the machine, and guiding means for correctly guiding the component tape into the machine.
The locking means is provided for ready, quick and accurate mounting of the tape guide into the component mounting machine. The locking means of the tape guide is arranged for interaction with corresponding locking means provided on the component mounting machine, thus providing both a correct positioning and a secure mounting of the tape guide. Preferably, the locking means is in the form of resiliently biased snap-in locking means, e.g. in the form of a latch and a recess provided on the tape guide interacting with axles provided on the component mounting machine, or in the form of a catch and an axle, respectively, provided on the component mounting machine interacting with corresponding protrusion and recess provided on the tape guide. As realised by a person skilled in the art, various types of snap-in locking means, or other sorts of quick couplings, can be used for ready and quick attachment and detachment of the tape guide into and from a component mounting machine.
The guiding means is provided for guiding the component tape to the correct position within the component mounting machine, such that the components to be picked by a pick-up head reaches the correct picking position. The guiding means is preferably in the form of opposing grooves extending from the distal end of the tape guide to the proximal end thereof.
According to a preferred embodiment of the present invention, the tape guide is provided with component tape retaining means for retaining the component tape such that the component tape is not accidentally displaced relative the tape guide, i.e. such that the tape guide can not move along the length of the component tape when the component tape has been loaded into the tape guide and before attachment of the tape guide into, or after detachment of the tape guide from, the component mounting machine, i.e. when the tape guide with the component tape is located away from the component machine.
Thereby, following loading of the component tape into the tape guide, and the related association of the component tape information to the identity of the tape guide, the tape guide is prevented from being accidentally removed from, or accidentally moved along the length of, the component tape. Thereby, the component tape, contained on a component tape reel, can be stored together with and attached to the tape guide. It also ensures that the tape guide, following association of the tape guide identity to the component tape information, is loaded with the very component tape who""s information has been associated with the identity of said tape guide. A further advantage is that the number of components remaining on the tape, as derived by the component mounting machine in the manner described earlier, can be stored and retrieved by the machine when the component tape is re-loaded. This information can of course be retrieved by any component mounting machine having access to the same information.
As mentioned above, the retaining means preferably prevents the component tape from being accidentally moved along the length of the tape guide. This ensures that when loading the component tape into the tape guide, the desired position of the component tape relative the component mounting machine, and its parts, can be chosen. The chosen position is then maintained until the component tape is deliberately released from the tape guide.
According to an embodiment of the invention, the tape guide is also provided with means for exposing a component to be picked at a picking position. This exposure means comprises separating means for separating and lifting a lateral portion of the cover from the component tape, leaving the remaining portion of the cover at least partially attached to the component tape, and for bringing the lifted portion of the cover aside such that the component to be picked can be exposed.
The use of such separating means eliminates the need for means handling the cover tape after removal from the component tape since the cover remains attached to the component tape. Thereby, the loading process is even further facilitated and the loading time is reduced, reducing the downtime of the mounting machine and positively effecting the efficiency of the entire manufacturing process.
After the component tape has been loaded into the tape guide, the tape guide can be connected to the tape reel, according to an embodiment of the invention, by arranging holding means on the tape guide for attachment of the tape guide to a tape reel. Thereby, the component tape reel can not be unrolled, and the tape reel can easily be stored together with the tape guide for quick mounting into a component mounting machine. According to an embodiment of the invention, the holding means comprises a clip for attachment of the tape guide to a tape reel. According to an alternative embodiment, the holding means comprises a piece of Velcro(copyright) on the tape guide engaging a corresponding piece of Velcro(copyright) provided on the tape reel. As realised by a person skilled in the art, various types of holding means are contemplated without extending beyond the scope of the present invention.
According to an embodiment of the present invention, the body of the tape guide is formed by an elongated open-ended profile with opposing elongated walls, and a base connecting said elongated walls. The walls are provided with the above described guiding means for guiding the component tape. The base is provided with an opening for receiving feeding means, provided in the component mounting machine or in a tape magazine arranged for insertion into the machine, for engagement with the component tape by protrusion through the opening and engagement with feeding holes provided on the component tape. Thus, the tape guide does not comprise any feeding mechanisms at all, which significantly reduces the manufacturing costs for the tape guide. It also reduces the size and weight of the tape guide, and facilitates the storing of the tape guide together with and attached to a component tape contained on a tape reel.
According to an aspect of the present invention, a tape magazine is provided for reception of at least one tape guide according to the invention, the magazine being provided with the corresponding locking means interacting with the locking means provided on the tape guide, said corresponding locking means otherwise being provided in the component mounting machine, as described above. The tape magazine is further provided with means for receiving at least one tape reel provided with a component tape, such that said reception can be performed when the component tape of the tape reel is loaded into the tape guide, and feeding means for feeding the component tape(s) towards the picking position. As described earlier, the magazine is also provided with means for receiving the identities of tape guides that are mounted into the magazine, along with means for transferring this information to a component mounting machine. The tape magazine is inserted to, or mounted or attached to, the component mounting machine and forms an intermediate device between the tape guide, with the loaded component tape and tape reel, and the component mounting machine, and feeds the components to their respective picking position within the machine.
In the above and following description of the present invention, for the purposes of storing information, associating information, retrieving information, etc., as described above, use is made of at least one database, to which the component mounting machine(s) have access. However, since any suitable database can be used with the invention, as realised by the man skilled in the art, the specifics of the database do not form part of the invention and will therefore not be further described.
Further details and aspects of the invention will become apparent from the following detailed description of embodiments of the invention, reference being made to the accompanying drawings, wherein like reference numerals refer to similar parts throughout.